一、国内外概况目前,国内外对空冷硬化钢,如高速钢和高碳不锈钢,绝大多数都采用纯度大于99.996%的氮气进行冷却淬火,以解决油淬火时如表面产生白层、变形大,给真空回火工艺增加麻烦。而对高碳铬钢轴承,由于气冷工艺不能保证硬度要求,一般淬火时均采用油淬火。但该钢种在真空淬火时,由于真空淬火油在较高真空下仍然满足不了所需要的冷却速度,目前,国内外在进行真空淬 First, at home and abroad Overview At present, the domestic and international air-cooled hardened steel, such as high-speed steel and high-carbon stainless steel, the vast majority of the purity of more than 99.996% of nitrogen for cooling quenching to solve oil quenching, such as surface white layer, large deformation , To increase the vacuum tempering process. The high-carbon chromium steel bearings, as the air-cooled process can not guarantee the hardness requirements, the general quenching oil quenching. However, the steel in the vacuum quenching, the vacuum quenching oil still can not meet the required cooling rate under high vacuum, at home and abroad in the vacuum quenching